Question

2+2²+2³+2⁴+...+2¹⁰⁰

ai giúp em với ạ

Answer 1

\(2\cdot A=2^2+2^3+...+2^{101}\)

\(\Leftrightarrow A=2^{101}-2\)

Answer 2

Đặt \(A=2+2^2+...+2^{100}\)

\(2A=2^2+2^3+...+2^{101}\\ 2A-A=\left(2^2+2^3+...+2^{101}\right)-\left(2+2^2+...+2^{100}\right)\\ A=2^{101}-2\)